Sony has introduced 2 new docks for the iPhone - one, a dual dock for iPod devices with DJ-style shelf system, called Xross Fade, while the other one is a multi-room audio system for iPod players, called S-Airplay.

The Xross Fade isn't exactly something professional DJs would use to rock a large party, but its 450 watts of total power output would give a good thump for a small party, where one could use it for mixing and playing music from an iPod player, CDs, and other music sources.
Xross Fade comes with a pair of two-way bass reflex speakers and a dual 7-inch subwoofer enclosure. It also has an interface and 2 scroll wheel mechanisms for touch-free menu navigation, as well as a USB recording function that saves mixing sessions to a USB device in the MP3 format without a PC.
Also bundled is an MP3 Booster+ feature that claims to improve audio quality. According to Sony, the beat blend feature adds a layer of pre-programmed percussion, drum sounds and drum loops over the mix, to get that extra thump.
The Xross Fade system includes traditional shelf system features, such as a CD player, an AM/FM tuner, and a line-in jack for listening to MP3 players. Users can mix music from these sources as well as their iPod players. The system also converts CDs and AM/FM radio.
All in all, this seems like a nice system that can be used by an aspiring DJ to start off.
The other product, the S-Airplay, is meant for home listening. The interesting thing about it is that it offers wireless multi-room solution without complicated setup requirements.
This is how it works - Wireless audio can be transmitted from the system's main docking station in one room to various rooms in the house, up to nearly 164 feet, by plugging a separate S-Air wireless speaker into a power outlet.
The system comes with one docking station and two S-Air wireless speakers, but it can transmit to up to 10 speakers simultaneously (additional speakers sold separately). It allows listeners in one room to hear a radio station, while listeners in another room can enjoy music from the iPod at the same time.
The Sony S-Airplay is expected to be available in September for $400.